In: Biology
Glycogen is treated with dimethyl sulfate, which adds a methyl group to every free OH group. Next, the molecule is hydrolyzed to break all the glycosidic bonds between glucose residues. The reaction products are then chemically analyzed.
Q1: How many different types of methylated glucose molecules are obtained?
Q2: Draw the structure of the one that is most abundant.
Note: The methylation of Glycogen-(branched polysaccharide with alpha(1,4) linkage in linear Glucose linkage & alpha(1,6) linkage at branch point) form Methyl ethers. These compounds are employed in the structural studies of polysaccharides & oligosaccharides.
When the hydrolysis of the methylated glycogen is done as the methyl group as not attached at glycosidic bonded hydroxyl groups they remain free of methyl groups after hydrolysis. Thus, we can find the branch points, branching nature and most clearly the linkage of glucose in a linear chine.
1. Mainly two different types of methylated glucose molecules are formed they are- 2,3,6 trimethyl-D-Glucose & 2,3 dimethyl-D-Glucose.
2. Among the two methylated glucose molecules 2,3,6 trimethyl-D-Glucose is most abundant and it's structure is in the following image:
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